Pipe mapping systems and methods

ABSTRACT

In one embodiment, a method for mapping pipes under inspection includes generating, from a video inspection camera inserted into a pipe, one or more images of the interior of the pipe, generating video camera velocity data, and determining, based at least in part on the one or more images and the velocity data, an estimation of the interior size of the pipe.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is a continuation of and claims priority to co-pendingU.S. Utility patent application Ser. No. 14/709,301, which is acontinuation of and claims priority to U.S. Utility patent applicationSer. No. 14/034,293, entitled PIPE MAPPING SYSTEMS AND METHODS, filedSep. 23, 2013 (now U.S. Pat. No. 9,041,794 issued May 26, 2015, which isa continuation of and claims priority to U.S. Utility patent applicationSer. No. 11/928,818 (now U.S. Pat. No. 8,547,428 issued Oct. 1, 2013)entitled PIPE MAPPING SYSTEM, filed Oct. 30, 2007, which claims priorityto U.S. Provisional Patent Application Ser. No. 60/864,104, entitledPIPE MAPPING SYSTEM, filed Nov. 2, 2006. The content of each of theseapplications is incorporated by reference herein in its entirety for allpurposes.

FIELD

This disclosure relates generally to electronic and mechanical systemsand methods for inspecting the interior of pipes and other conduits.More specifically, but not exclusively, the disclosure relates tosystems for inspecting and mapping pipes using sondes in conjunctionwith utility locators or other related devices.

BACKGROUND

There are many situations where it is desirable to internally inspectlong lengths of pipe that are already in place, either underground, in abuilding, or underwater. For example, sewer and drain pipes frequentlymust be internally inspected to diagnose any existing problems and todetermine if there are any breaks causing leakage or obstructionsimpairing the free flow of waste. It is also important to internallyinspect steam pipes, heat exchanger pipes, water pipes, gas pipes,electrical conduits and fiber optic conduits for similar reasons.Frequently, pipes that are to be internally inspected have an internaldiameter of six inches or less. It is sometimes necessary to inspectseveral hundred feet of pipe.

In the existing art, video pipe inspection systems may include a videocamera that is forced down the pipe to display the pipe interior on avideo display. The inspection is commonly recorded by means of a videorecorder (VCR) or digital video disk (DVD). Conventional video pipeinspection systems may include a semi-rigid push cable that provides anelectromechanical connection between a ruggedized camera head assemblyenclosing and protecting the video camera and a rotatable push reel usedto pay out cable and force the camera head assembly down the pipe. Thevideo push cable must be specially designed to be flexible enough tomake tight turns yet rigid enough to be pushed hundreds of feet downsmall diameter pipe and should also incorporate electrically conductivecable having the proper conductors and impedance for conveying the NTSCor other video signals to the video display unit and for coupling toexternal power and ground conductors. Examples of suitable video pushcables are disclosed in co-assigned U.S. Pat. No. 5,457,288 issued Oct.10, 1995 to Mark S. Olsson and U.S. Pat. No. 5,808,239 issued Sep. 15,1998 to Mark S. Olsson.

A conventional video pipe inspection system may include a reel insidewhich the video push cable is wound for storage. The reel may besupported on a frame for rotation about a horizontal or a vertical axisfor paying out the video push cable and for rewinding the video pushcable for storage about the reel. This may require adding a slip ringassembly into the hub and/or axle of the reel to continue electricalconnections between the proximal end of the video push cable andexternal circuits that power the video camera head assembly and receivevideo signals therefrom. The usual slip ring assembly is expensive andprone to failure. The frame and axle that rotatably support the reelalso represent additional bulk and expense.

The video camera head assembly design and the manner in which it isconnected to the distal end of the video push cable is critical to theperformance and reliability of a video pipe inspection system. Thesestructures must be rugged, yet the camera head assembly must be compactand its manner of connection to the video push cable flexible enough tobend through tight turns. It is also desirable to incorporate anelectromagnetic transmitter near the video camera head assembly toprovide a radiated signal from which the camera head position may beconfirmed at a remote above-ground locator instrument. Heretofore thesignals radiated from such transmitters have been inherently weak,making it difficult to precisely determine the underground position ofthe inspection assembly with a remote locator.

Existing systems known in the art provide the operator little more thandirect video image information, sometimes time-tagged by frame inrecording. Most existing systems may provide a disoriented video imagewhenever the camera head assembly rotates away from alignment with thelongitudinal axis of the pipe being inspected because of such issues asuncontrolled push cable torque or navigation through a bend or joint inthe pipe. Video images from existing systems is provided with a singleuniform (usually only moderate) resolution. Existing systems provide nomeans for tracking changes in camera orientation and distance traversedin the subject pipe or conduit nor to generate a map of the pipe fromcamera travel distances and headings.

Accordingly, there is an unmet need in the art for a pipe inspectionsystem that can provide internal pipe images with accurate location andorientation information. Moreover, there is also a continuing need inthe art for a pipe inspection system that can provide the location andorientation data required to provide an accurate mapping of the pipeunder inspection to an operator, as well as provide other advantages.

SUMMARY

In accordance one aspect, the present disclosure describes anadvantageous enhancement to pipe inspection systems by, integratingmultiple local condition sensors with the camera head assembly in thepipe inspection assembly and by providing an improved informationdisplay format and system, an improved cable-counting method, and/orimproved methods for detecting, analyzing and relaying data fordetermining camera location and environment in real time during a pipeinspection. This disclosure also describes a system and method forgenerating a three dimensional (3D) pipe mapping image on a display inreal time from data received from a pipe inspection assembly.

Various additional aspects, features, and functions are furtherdescribed below in conjunction with the appended drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure may be more fully appreciated in connection withthe following detailed description taken in conjunction with theaccompanying drawings, wherein:

FIG. 1 is a schematic diagram illustrating an exemplary embodiment ofthe pipe mapping system showing a pipe inspection assembly havingvarious local condition sensors at one end of a transmission cablecoupled to a cable-counter at the pipe entry head;

FIG. 2 is a detail diagram of the system of FIG. 1 illustrating anoblique view of a rectangular native camera head assembly image, anintermediate cropped circular processor image, and a circular“radar-scope” display image realigned with true vertical;

FIG. 3A is a block diagram illustrating an embodiment of the processingflow of accelerometer data, compass data, gyro data, cable counter datafor the system of FIG. 1 ;

FIG. 3B is a schematic diagram illustrating an embodiment of theprocessing flow of several cable count and pointing vector data layersto form a composite path representing a camera trajectory through a pipeunder inspection for the system of FIG. 1 ;

FIG. 3C is a schematic diagram illustrating the merger of a trajectorymap sequence to form a 3D image of a piping system for the system ofFIG. 1 ;

FIG. 3D is a schematic diagram illustrating the transfer of pipe mappingdata between a processing and display unit and a local data store/remotedata store for the system of FIG. 1 ;

FIG. 4 illustrates a screen display image suitable for representing apipe inspection camera image together with a second embedded image frameshowing camera track display image;

FIG. 5A is a schematic diagram of a pipe mapping system embodimentillustrating the detection of an integral Sonde during pipe inspection;

FIG. 5B shows the scene from FIG. 5A modified to illustrate tracking ofan integral Sonde through a bend during pipe inspection;

FIG. 6 illustrates the selection for display from a series of videoimages and a high resolution still image under manual or processorcontrol in a pipe mapping system embodiment;

FIG. 7A is an oblique cut-away view of a system push-cable embodimenthaving a composite core surrounded with power and/or data conductors andhaving an optional central optical fiber for transmitting optical datasignals; FIG. 7B is a cross-sectional view of the system push-cable ofFIG. 7A;

FIG. 8 is a schematic diagram illustrating an embodiment of theprocessing flow of cable counter, accelerometer, compass, and cameradata to form a series of digital images for a pipe mapping systemembodiment;

FIG. 9 is a schematic diagram of a pipe mapping system embodimentillustrating the processing flow of Sonde drive-circuit loading data todisplay ferromagnetic pipe properties;

FIG. 10A is a schematic diagram of a pipe mapping system embodimentillustrating a length of cable with a EMF sensor revealed in theinspection assembly, and the integral Sonde at a known distance, withthe camera head assembly and sensor axially aligned relative to theSonde;

FIG. 10B illustrates the separation of the EMF sensor and Sonde in apipe bend for the system of FIG. 10A;

FIG. 11 is a schematic diagram of a pipe mapping system embodimentillustrating the camera cable emanating an injected locating frequencyand a locator above ground being used to measure the location of theinspection assembly;

FIG. 12A is a schematic diagram of a pipe mapping system embodimentillustrating a inspection assembly with EMF sensor axially aligned withthe cable to which a locating frequency has been coupled using abuilt-in transmitter;

FIG. 12B shows the inspection assembly of FIG. 12A with the cable andEMF sensor unaligned within a leaky bent pipe;

FIG. 13 is a schematic diagram of a pipe mapping system embodimentillustrating a cutaway view of the inspection assembly having anacoustic transducer for producing sonic detection patterns for transferto a data processing and a display assembly;

FIG. 14A is a schematic diagram of a pipe mapping system embodimenthaving a detachable cable-counter embodiment disposed at the entrance ofthe pipe;

FIG. 14B is a schematic diagram of a pipe mapping system embodimenthaving a cable-counter embodiment integral to a cable-feed drivemechanism;

FIG. 15 is a schematic diagram illustrating an embodiment of theprocessing flow for extracting apparent velocity vector data fromdigital image data, including apparent velocity data, surface variationdata and track and map data;

FIG. 16A is an expanded view of a flexible inspection assemblyembodiment having an in-line ferromagnetic Sonde embodiment with acentral tube for the passage of electrical conductors and/or fiber opticcables;

FIG. 16B is another view of the assembly of FIG. 16A revealing theelectrical connectors in the push cable;

FIG. 16C is a cross-section of the Sonde of FIG. 16A;

FIG. 16D is a cross-section of an alternate in-line ferromagnetic Sondeembodiment without a central tube;

FIG. 17 is another view of the assembly of FIG. 16A revealing the innercamera cable conductors and the electrical connectors to the camera headassembly;

FIG. 18A is an expanded isometric view of a slip-ring embodimentsuitable for transmitting electrical power and data signals across arotating storage drum assembly for the system of FIG. 1 ;

FIG. 18B is an expanded isometric view of an alternate slip-ringembodiment having a “pancake” configuration;

FIG. 18C is another view of the slip-ring of FIG. 18B;

FIG. 19A is a rear view of a push-cable storage drum embodiment showingthe frame supported with spring mounts on wheels;

FIG. 19B is a detailed view of wheel, axle and bottom frame embodimentsfor the push-cable storage drum of FIG. 19A;

FIG. 20 is a front perspective view of the storage drum of FIG. 19Arevealing the handle, frames, support tubes, wheels, drum and rotaryhub;

FIG. 21 is a front perspective view of an alternative storage drumembodiment revealing tubes, frame, wheels, battery mounts, and exemplarybatteries;

FIG. 22A is a detail view of an exemplary storage drum assembly handleembodiment illustrating the joint between a molded plastic frame memberand a support tube;

FIG. 22B is a detail view of the joint of FIG. 22A illustrating thedisposition of two pressure-expanded dimples for joining the supporttube to the plastic frame member;

FIG. 22C illustrates an alternative embodiment of the joint of FIG. 22Billustrating the forced seating of the pressure-expanded support tubedimples into a groove molded into the plastic frame member;

FIG. 22D illustrates an alternative embodiment of the joint of FIG. 22Billustrating the forced seating of the pressure-expanded support tubedimples into matching holes molded into the plastic frame member;

FIG. 23A is a cutaway side view of a partially disassembled inspectionassembly embodiment revealing the camera head assembly, the push-cable,the terminating assembly, the locking device, the coil spring, and theinternal connectors;

FIG. 23B is a cutaway side view of the fully-assembled inspectionassembly of FIG. 23A;

FIG. 23C is a cutaway side view of an alternative embodiment of thefully-assembled inspection assembly of FIG. 23B;

FIG. 24A is a front perspective view of the storage drum of FIG. 19 withan exemplary display monitor embodiment fixed to the storage drum frameand fitted with a hinged sunshade;

FIG. 24B illustrates the two extreme positions of the hinged sunshadefor the monitor of FIG. 24A;

FIG. 24C is a front view of the monitor of FIG. 24A showing the hingedsunshade in the closed position for compact display protection duringtransit;

FIG. 25A is a schematic diagram of a cable drum embodiment having animage cable for transferring image data and a wireless transmission unitfor transferring local condition sensor data to the processing unit;

FIG. 25B is an alternate embodiment of the storage drum of FIG. 25Ahaving a wireless transmission unit for transferring all data to theprocessor;

FIG. 26 is a front perspective view of the storage drum of FIG. 19having a tool tray or box mounted to the back of the cable drum supportframe near the handle, having a USB port fixed to the cable-drum supportframe for linking to a laptop.

FIG. 27 is a schematic diagram illustrating an embodiment of theprocessing flow of sensor data packets to the processor and an exemplarydisplay image showing the insertion of sensor data in the margins arounda circular image display;

FIG. 28 is a schematic diagram of a pipe mapping system embodimentillustrating the use by an operator of a wireless remote control torecord a wirelessly sent voice notation or to send commands to thecamera unit or other system elements by way of the processor; and

FIGS. 29A-C are schematic diagrams illustrating structured-lighttechniques adapted for use in a laser-driven pipe inspection cameralighting unit.

DETAILED DESCRIPTION OF EMBODIMENTS Overview

This application is related by common inventorship and subject matter tothe commonly-assigned patent application Ser. No. 10/268,641, filed onApr. 15, 2004 and published on Apr. 15, 2004 as U.S. Patent ApplicationPublication No. 2004/0070399A1, and the commonly-assigned patentapplication Ser. No. 10/308,752, filed on Dec. 3, 2002 and published onApr. 15, 2004 as U.S. Patent Application Publication No. 2004/0070535A1,both of which are entirely incorporated herein by this reference.

This application is also related by common inventorship and subjectmatter to U.S. Pat. Nos. 5,808,239 and 5,939,679, both issued to Mark S.Olsson, and U.S. patent application Ser. No. 10/858,628, filed on Jun.1, 2004 by Mark S. Olsson et al. and published on Dec. 15, 2005 as U.S.Patent Application Publication No. 2005/0275725A1, all of which areentirely incorporated herein by this reference.

Termination assemblies suitable for use in the proximal and distal endsof a video push cable are disclosed in U.S. Pat. No. 6,958,767 issued toMark S. Olsson et al., which is entirely incorporated herein by thisreference.

This application is also related by common inventorship and subjectmatter to U.S. Patent Application 2006/0006875, published Jan. 12, 2006by Mark S. Olsson, et al., now U.S. Pat. No. 7,221,136, and U.S. PatentApplication Publication No. 2005/0275725 published Dec. 15, 2005 by MarkS. Olsson et al., both of which are entirely incorporated herein by thisreference.

The improvements described herein may also be implemented in a videopipe inspection system embodiment of the general type disclosed in U.S.Pat. No. 6,545,704, issued Apr. 18, 2003, and entirely incorporatedherein by this reference.

FIG. 1 is a schematic diagram illustrating an exemplary pipe mappingsystem embodiment 99 showing a pipe inspection assembly 103 having aninspection camera head assembly 100 incorporating an image sensor 102,and also having a three-axis compass 108, a three axis accelerometer126, a three-axis gyroscopic (“gyro”) sensor 104, and a temperaturesensor 106, each for producing a sensor data signals responsive to therespective local physical condition. Pipe inspection assembly is coupledto a push cable 101, which is stored and extended from the cable storagedrum unit 124 proximate to a cable counter 110 for counting the lengthin feet or meters of push cable 101 extending into a pipe 116 underinspection. Image sensor 102 is disposed at the front of camera headassembly 100 (at the very front of inspection assembly 103) so that thefield of view (FOV) of image sensor 102 includes the entirecircumference of the adjacent interior pipe wall (not shown). Localcondition sensor data along with video or still images of this FOV aresent back over suitable conductors (not shown) in push cable 101 to adata processor 112 and an image display 114. Gyro sensors 104 senseinspection camera rotation around each of three sensing axes. Atemperature sensor 106 provides temperature at the inspection camera.Gyros are particularly useful if the earth's magnetic field is distortedby residual magnetism or adjacent ferromagnetic materials. An integralSonde 122 is partially revealed in FIG. 1 . The power and dataconductors (not shown) in push cable 101 are coupled to the camera cable(not shown) by a mating plug 118 or termination.

The rectangular image produced by an inspection camera may be croppedand reoriented to provide a circular “radar-screen” type image correctlyaligned with the pipe at the display. FIG. 2 is a detail diagram ofsystem 99 (FIG. 1 ) showing image sensor 102 in camera head assembly100, which produce a raw, rectangular image 202 of the interior of apipe (not shown) for transmission as digital information to a processor112 wherein the image 202 is reconfigured into a circular image 204. Theprocessor 112 then rotates image 204 to reorient it responsive to sensordata from accelerometer 126 and/or gyroscopic sensors 104 (FIG. 1 ).Because sensors 104 and 126 detect rotation of camera head assembly 100,these sensor signals may be used to compute the angular rotation of thecamera feed with respect to the pipe under inspection. Adjusting theorientation of display image 204 responsive to these sensor dataproduces the correctly oriented circular “radar-scope” display image206, which is then transmitted from processor 112 to the display unit112. The display image 206 resulting from this process orients the pipebottom at the display bottom independently of the camera head assemblyorientation within the pipe.

This disclosure is directed to a method of capturing complete pointingvector information for individual images at different instants in timethat facilitates the generation of a tracking map and athree-dimensional (3D) representation of the pipe during inspection. Aninspection path track image may be displayed with the camera head image,for example. FIG. 3A is a block diagram illustrating a processing flowembodiment 300 of accelerometer data 316, compass data 328, gyro data319, and cable counter data 318. The accelerometer data 316 are combinedwith the magnetic compass data 328 to produce a camera head assemblypointing vector 322, which is then associated with the current cablecounter step increment 318. It may be reasonably assumed that theinspection camera pointing direction is approximately parallel with theaxis of the pipe under inspection when moving therein. A cable countervalue 318, accelerometer data 316, gyro data 319, and compass data 328are sent to the system data processor 320, which responsively produces apointing vector value 322 indexed to footage counter output (N) 318. Thepointing vector value 322 is integrated by the processor 320 into acomposite image for the video display 326 and the data are also storedin the memory 324, which may be embodied as volatile, nonvolatile, or acombination thereof.

Camera motion vectors represent a combination of speed and time andtherefore length traveled. Motion vectors may be accumulated using afixed time interval between data samples over a varying length, or byusing fixed lengths between data samples over varying intervals or somecombination of the two methods. FIG. 3B is a schematic diagramillustrating a motion vector processing embodiment. If the length ofeach of these pointing vectors is set to the distance that theinspection cameras moves, which corresponds to each cable-counter stepincrement, then linking this series of motion vectors end to endprovides a map of the approximate inspection camera trajectory throughthe piping system under inspection. In FIG. 3B, several exemplary motionvector values 302, 304, and 306 are combined in the processor 320 (FIG.3A) to form a composite camera path 308, which may be displayed on aninset window on the image display 326 (FIG. 3A) or as a video imageoverlay. By this process, a 3D map of the piping path may be createdsimply by sampling camera motion vectors while passing the inspectioncamera through the piping system under inspection. Any useful displayknown in the art is suitable for displaying the piping path image to theinspection operator.

FIG. 3C is a schematic diagram illustrating the merger of a trajectorymap sequence to form a 3D pipe system map image. A series of motionvector data 310 are integrated into a trajectory map 312 and are thencombined with additional local condition sensor information to produce a3D integrated drawing 314 of the pipe system as it has been traversed.

The pipe mapping data may be stored by any known means and subsequentlyretrieved for later viewing or evaluation. FIG. 3D is a schematicdiagram illustrating the transfer of pipe mapping data between aprocessing and display unit and a local data store/remote data store.The accelerometer data 316, cable count data 318, compass data 328, andother sensor data 332 are sent to the data processor 334, which loadsthe data into volatile memory storage 336, manages the writing of thedata to non-volatile memory 338 (for example, a flash memory unit, card,disk or the like) and assembles display updates for implementation inthe display 340. These pipe mapping data may be added information to aGeographical Information System (GIS) Database of known utilitylocations, for example, to improve future locate operations and reducethe risk of accidental damage to the pipe from excavation at the wronglocation.

FIG. 4 illustrates a screen display image suitable for representing apipe inspection camera image together with a second embedded image frameshowing the real time camera track display image. The system displayscreen 114 shows a centrally located circular image 406 portraying thecamera view corrected for the inspection assembly roll orientationdeduced from accelerometer or gyro data. A small display window 404portrays the 2D camera track as it is composited in real time.Alternatively, small display window 404 may show a 3D image of the pipemap instead of or in addition to the 2D track.

The system of this the disclosure is directed to may include a dipoleSonde attached to or near the inspection assembly or integratedtherewith to facilitate operator measurement of camera depth belowground at any moment. FIG. 5A is a schematic diagram of a pipe mappingsystem embodiment 501 in which the depth (A) 504 of the inspectionassembly 503 below some reference surface, such the earth's surface 505,is measured by using an electromagnetic Sonde locator 500 to locate aSonde 122 in or adjacent to the inspection camera head assembly 100. Thelocator's computed measurement depth (A) 504 from ground level 505 tothe integral Sonde 122 is shown. Locator 500 is disposed at the groundlevel 505 above a buried pipe 116 in which a push-cable 101 affixed tothe inspection assembly 503 incorporating the integral Sonde 122 andcamera head assembly 100 with image sensor 102 (FIG. 1 ) is disposed asit is during inspection of pipe 116. A removable cable count device 110is affixed to the head of pipe 116. The processor unit 112 and displayunit 114 are illustrated as being disposed on the far side of the cablestorage drum unit 124. In this configuration, for example, the locator500 detects inspection assembly 503 at the distal end of cable 101 andcomputes the depth value (A) 504. Information from the locator 500 issent to the processor unit 112 through the wireless data link 502. Theinformation sent to the display 114 may include the detected depth (A)504 for use in rendering the tracking map 506, for example. The 3D trackof the camera head assembly may also be measured by a locator, and thesemeasurements transmitted to the camera controller. Alternatively, thecamera track information measured by the camera control unit from localcondition sensor and cable-count may be sent to the locator by wire orwireless means. FIG. 5B shows the scene from FIG. 5A modified toillustrate tracking of an integral Sonde 122 through a bend during pipeinspection and illustrates three Sonde positions (a, b, c). Data aretransmitted wirelessly from locator 500 to processing unit 112 anddisplay unit 114 through link 502 using a data transfer protocol such asIEEE 802.15.4, for example. Depth values 508, 512 and 514 for therespective illustrated Sonde positions (a, b, c) are each displayed astext lines exemplified by the text line 510 on the display 114. Thelocator 500 may be moved through a series of search and detectionlocations selected according to the detected motion of the inspectionassembly 503. Depth values are computed by the locator for the threeillustrated positions of the inspection assembly 503, and reported forpresentation as a text line 510 on the display 114 based on signaldetection (X, Y, Z), sonde position and orientation (not shown), anddepth computation at the locator 500 or of processor 112.

The system of this the disclosure is directed to may include means forautomatically or manually switching the camera head image from lowresolution display (for example, while the camera is moving) tohigh-resolution display (for example, when the camera stops moving) toprovide improved opportunity for detailed inspection. FIG. 6 illustratesthe selection for display of a high resolution still image 604 from aseries 602 of video images under manual or processor control.

The camera head assembly includes an imager that can send images ineither of video format or higher resolution sequential still images. Thesystem's image transmission bandwidth may be devoted to high frame-ratetransfer of low-resolution images, or low frame-rate transfer of highresolution images, depending on camera motion or operator preferences.The particular images transmitted by the camera head assembly 100 may beselected by manual operator control or by automated means responsive tochanges in camera head assembly motion, such as switching ofhigher-resolution images when the inspection assembly 503 stops moving.Changes in image transmission characteristics may be automaticallycontrolled by either the camera head assembly 100 or by the dataprocessing and image display system 112 in cooperation with the camerahead assembly 100. Motion changes may be detected in data fromaccelerometer 126 (FIG. 1 ) or from the image data changes or any usefulcombination thereof. A higher resolution image may be transmitted fordisplay and/or storage whenever the camera head assembly motion halts.The inspection camera operator viewing the display perceives thishigher-resolution as a sharper and more detailed view of the camera FOVwhenever pausing camera motion through the piping system underinspection. This enhanced view is presented seamlessly without operatoraction beyond pausing camera head assembly motion. High-power strobeLEDs (not shown) are useful for illuminating the camera FOV forsynchronous high-resolution imaging, for example.

The direction and distance of integral Sonde motion may be determinedfrom the Sonde detection by an advanced Sonde locator; such as, forexample, the locator disclosed in U.S. Pat. No. 7,009,399B2 issued toMark S. Olsson, et al. and entitled “Omnidirectional Sonde and LineLocator,” which discloses an electromagnetic locator 30 that may includea GPS receiver as described at Col. 13, lines 59-61, the content ofwhich is entirely incorporated herein by this reference. The resultingSonde locate data may be used to improve the pipe mapping accuracy byaugmenting existing data from compass and accelerometer sensors inenvironments where these sensors are less accurate, such as in thepresence of certain large ferromagnetic bodies, for example.

FIG. 6 illustrates a series of low-resolution images 602, each of whichis associated (labeled) with a different cable-count tag represented bythe value (N) shown in feet or meters, for example. In this example, theimages 602 represent the camera FOV as it approaches a root 605 that haspenetrated the pipe wall. The forward motion of the camera is paused, atN=125, whereupon the image transmission may switch to thehigh-resolution image 604 shown, to facilitate improved inspection andevaluation. This automatic switch to high-resolution imaging may bemanually controlled via external switch or processor controlled based ona pause in motion detected via an accelerometer or other motion detectorthrough the pipe, for example.

The system of this the disclosure may include a push-cable used ininspection formed around a resilient composite rod core with a centralglass or plastic optical fiber for transferring optical datarepresenting images and local condition sensor data to a processor and adisplay system. FIG. 7A is an oblique cut-away view of a systempush-cable embodiment 701 having a composite core 702 surrounded withpower and/or data conductors 704 and having, for example, a centraloptical fiber 710 for transmitting optical data signals. One or moreoptical data transmission fibers exemplified by the fiber 710 may beplaced near the central axis of the resilient composite rod 702 insideinspection camera system push-cable 701. Optical fiber 710 is useful fortransmitting high-resolution imaging data and other information from theinspection assembly 103 to a data processor 112 and image display 114(FIG. 1 ). FIG. 7B shows a detailed cross-sectional view of thepush-cable 701 with the composite (e.g., fiberglass) core 702 having acentrally embedded fiber-optic cable 710 surrounded by other data and/orpower conductors (e.g., 704) wrapped in a shielding layer 706 and allenclosed by a resilient outer protective covering 708.

Another data processing system embodiment produces a series oftime-tagged digital images combined with data from the accelerometer,compass and other sensors to facilitate computation of a relative motionestimate and an analysis of the relationship between images. FIG. 8 is aschematic diagram illustrating a processing flow embodiment 800 forforming a sequence of digital images 810 representing a combination ofcable counter data 804, accelerometer data 802, compass data 805, andcamera image data on fiber optic cable 818. A continuous digital stripimage of the inside of the pipe under inspection is generated by thedata processing system 112 as the camera head assembly 100 is pushedthrough the piping system under inspection (FIG. 1 ). The accelerometerand cable-counter data 802 and 805 are useful for estimating therelative camera motion with respect to the piping system to assess thespatial relationship of the images within the sequence 810. Images fromfiber optic cable 818 are channeled through an analog to digitalconverter (ADC) 808 to the data processor 806. Additional data from acable-counting means 804, an accelerometer 802, and a plurality n ofother sensors 816 are combined in the processor 806 to generate thesequence of images 810, which are time-tagged and linked with otherappropriate data, temporarily maintained in a volatile memory 814, andultimately written to a non-volatile data store 812.

The complex load impedance of the Sonde drive circuit may be employed tofacilitate detection of local ferromagnetism in the piping material.FIG. 9 is a schematic diagram of a pipe mapping system embodiment 900illustrating the processing of Sonde drive-circuit loading data toproduce a display of pipe ferromagnetism. The display system 114provides a visual indicator 902 when the system detects ferromagnetismin the pipe. In system 900, the loading or phase shift of theelectromagnetic Sonde drive circuit (not shown) may be analyzed forevidence of ferromagnetic loading of the Sonde output radiation. Thisdrive circuit output impedance analysis may be calibrated and/orverified with, for example, any data from the electronic compass sensor108 (FIG. 1 ) or any other useful evidence suggesting local magneticperturbation. The display system 114 may provide any useful visualindication of local ferromagnetism (e.g., a pipe symbol 902 may bechanged from yellow to red). An inspection assembly 903 incorporating acamera head assembly 100 and a Sonde is urged by a push cable 101 into apipe 116 under inspection. The Sonde electromagnetic dipole field 904interaction with the local radiation impedance presented by the pipe 116and other local elements gives rise to Sonde driver output loadmagnitude and phase changes 908 in the usual manner. These changes 908are measured and analyzed by a load analysis subroutine 910 in theprocessor 112. The indicator 902 on the display 114 provides theoperator with a ferromagnetic environment signal, for example, based onthe dynamic load analysis.

In another embodiment, a Sonde and camera head assembly are coaxiallydisposed within the inspection assembly, wherein one or more sensorsthat can detect the Sonde's emitted signal frequency are disposedaxially at a known distance from the Sonde to provide a signal changedetection when the camera head assembly turns with respect to the Sondeaxis, and also to provide an indication of changes in localelectro-conductive and/or ferromagnetic characteristics.

In another embodiment, a high-frequency locating signal emitter iscoupled to the camera push cable such that the signal may be activatedand deactivated by the operator or by automatic processor control,thereby providing a traceable signal for facilitating detection of thepath and depth or distance of the cable emitter as an aid in mapping theconduit or pipe. FIG. 10A is a schematic diagram of a pipe mappingsystem embodiment 1001 having an inspection assembly 1003 incorporatingthe camera head assembly 100, and an EMF sensor 1002, with an integralSonde 122 disposed at a known distance from sensor 1002. Sonde 122 isdisposed substantially coaxial to the inspection assembly axis ofsymmetry and is displaced along this axis from the inspection camera bya fixed predetermined distance. When the camera head assembly 100 turnsoff of the inspection assembly axis, changes in the Sonde signalstrength at sensor 1002 may be used to detect this turning motion, aswell as any changes in local ferromagnetism. Alternatively, the Sondedrive circuit (not shown) may be periodically re-tuned to reflectcompass sensor data output. In FIG. 10A, the inspection assembly 1003 isequipped with the integral Sonde 122 and electromagnetic sensor 1002adapted to sense the dipole field generated by the Sonde 122, isdisposed at a known distance from the Sonde 122. The inspection assembly1003 is situated in a straight segment of pipe with the result thatSonde 122 and the sensor 1002 are coaxially disposed.

FIG. 10B shows how the alignment of the Sonde 122 and sensor 1002changes responsive to bending of the flexible inspection assembly 1003during movement through a bend 1004 in the pipe under inspection. Thisrealignment is reflected in the modulation of a signal produced by thesensor 1002, which is processed at the processing unit 112 to produce acorresponding change in the display 114. A change in signal from theSonde 122 as measured at the sensor 1002 also occurs responsive tochanges in the ferromagnetic or electro-inductive properties of theenvironment adjacent to the inspection assembly 1003, such as changesoccurring during transition from nonmagnetic ABS pipe to ferromagneticiron pipe, for example.

FIG. 11 is a schematic diagram of a pipe mapping system embodiment 1100wherein the camera push cable 101 radiates an EM signal arising from aninjected high-frequency (HF) locate signal. A locator 500 above groundis used to measure the location of the camera head assembly. Data fromthe locator 500 are wirelessly transmitted to the processor 112 on link1106. A cable-counter 110 is disposed at the pipe entrance to sendscable indexing data to the processor 112. An external transmitter 1104and an inductive clamp 1116 may be used to inject the HF locate signalbut any other useful signal injection means known in the art may be usedfor this purpose. The injected HF signal may be continuous wave (CW) oractivated and deactivated under manual operator or automatic processorcontrol. The HF signal current may be measured and the measured currentvalue used, in combination with the deployed cable length from cablecounter 110, to infer useful information about the electromagneticproperties of the piping system under inspection. The inspectionassembly 1103 is shown at the end of a push-cable 101, which emergesfrom a pipe entry point supplied with a removable cable-count means 110.The cable may be connected by inductive clamp 1116 to an externaltransmitter 1104 whose other terminal is attached to a ground stake1108.

Alternatively, another useful injection embodiment directly couples atransmitter 1118 built into the cable storage drum assembly 124 to thepush-cable 101. The cable drum 124 may be fitted with a built-inline-locating transmitter 1118 and an innovative grounding device in theform of a metallic grounding mat 1110. FIG. 11 shows this alternativegrounding method, which is suitable for hard surfaces, such as concretepads, where a ground stake cannot be used. Grounding mat 1110 isconnected electrically to the built-in transmitter 1118. The groundingmat 1110 may be rolled up for storage when not in use and consists of ametallic cloth of chainmail or similar construction that is flexible andsufficiently dense to provide ground contact when spread out. A linelocator 500, preferably of a self-standing type, is used to detect thelocation of the energized push-cable 101 by tracing the injected signalfrequency. Data from the locator 500 are transmitted by wireless link1106 to the pipe inspection system processor 112 and processed to renderthe image 1114 on the display unit 114. Optionally, camera data can besent from cable drum 124 to display unit 114 by wireless link 1120.

In another aspect of this embodiment, an electromagnetic field (EMF)sensor for the locating signal frequency of the transmit cable is placedin the inspection assembly 1203, FIG. 12A, providing for the detectionof changes in the angular alignment of the camera head assembly 100relative to the push-cable 101 (as in starting a bend in the pipe) andetection of changes in the electro-conductive or ferromagneticproperties around the inspection assembly 1203, such as whenencountering an area near a leak in a pipe, or transitioning fromplastic to steel or iron pipe. FIG. 12A is a schematic diagram of a pipemapping system embodiment 1200 illustrating a camera head assembly 100with an EMF sensor 1202 axially aligned with the push-cable 101 to whicha locating signal 1206 has been coupled using a built-in transmitter1204. FIG. 12B shows the camera head assembly 100 with the cable and EMFsensor unaligned within a leaky bent pipe. For straight sections ofpiping the cable is approximately coaxial with the inspection cameraaxis of symmetry and aligned axially at some fixed distance from theinspection camera. Changes in the strength of the cable locating signal1206 measured at the inspection assembly 1203 occur as a direct resultof camera head assembly 100 turns with respect to the cable axis andchanges in local ferromagnetic or dielectric properties. Thisinformation is useful for localizing a pipe leak 1208 that is injectingfluid (e.g., water) into the soil surrounding the pipe.

In FIG. 12A, an inspection assembly 1203 is shown traversing theinterior of a pipe 116 and connected to a push cable 101. The inspectionassembly 1203 is equipped with a camera head assembly 100 and an EMFsensor 1202 of an appropriate frequency sensitivity. A built-intransmitter 1204 is connected internally to the push-cable 101 leadinginto the pipe 116. A predetermined locating signal 1206 is thus coupledonto the push-cable 101 to which EMF sensor 1202 can respond. In FIG.12A, the inspection assembly 1203 is disposed in a straight segment ofpipe 116 so that EMF sensor 1202 and the push-cable 116 are axiallyaligned. In FIG. 12B, a pair of sensors (not shown) disposedorthogonally to the z-axis of the inspection assembly 1203 can sensechanges in relative orientation between the inspection assembly 1203 andthe push-cable 101 behind it. In FIG. 12B, the same inspection assembly1203 is negotiating a bend in the pipe so that the sensor 1202 is nolonger axially aligned with the push-cable z-axis. This changes thelocating signal 1206 detection at the sensor 1202, which change may beanalyzed in processing (not shown) to render some indication on thedisplay (not shown), such as a change in the tracking line, for example.FIG. 12B also shows a leak 1208 in the pipe 116. In this example, such aleak of water or other conductive liquid operates to modify theelectro-conductive characteristics of the surrounding soil adjacent tothe sensor 1202 and push-cable 101, thereby changing the injected signal1206 detection at the sensor 1202. By analyzing the character of such adetection change, the processor may alert the operator to thecorresponding change in the camera head assembly environment.

FIG. 13 is a schematic diagram of a pipe mapping system embodiment 1300showing a cutaway view of the inspection assembly 1303 revealing thecamera head assembly 100, the EMF sensor 1302 and an acoustic transducer1306 for producing sonic detection patterns for transfer to a dataprocessor 112 and a display 114. The acoustic transducer 1306 may bemounted inside or outside of the inspection assembly 1303. Acousticcharacteristics may be analyzed to estimate the interior pipe surfacecondition as the inspection camera slides along the pipe 116. Fluidleaks may also be detected and localized by sensing the sounds generatedthereby. In FIG. 13 , a inspection assembly 1303 is equipped with anacoustic transducer 1306 and is shown traversing the interior of a pipe116. Signals from the sonic transducer are routed through an ADC (notshown) to digitize the acoustic signals for transfer to processor 112wherein they are processed to provide information concerning theconditions within the pipe 116, the presence of leaks, etc.

FIG. 14A is a schematic diagram of a pipe mapping system embodiment 1400having a detachable remote cable-counter embodiment 1402 disposed at theentrance of the pipe 116. Remote cable-counter 1402 is mounted at thecable entry point into the piping system under inspection to improveinspection accuracy by providing a more accurate measurement of cabledistance to the camera head assembly. Wireless link 1404 communicatesthe cable distance measurement data to the data processing system 112where the data are integrated into the information display 114. Thewireless data link 1404 may embody any useful protocol known in the art,such as Zigbee, IEEE 802.15.4, or Bluetooth, for example.

FIG. 14B is a schematic diagram of a pipe mapping system embodiment 1401having a fixed cable-counter embodiment 1408, which is integral to thepowered cable-feed drive unit 1406 that is mounted at the entry point tothe pipe under inspection during use. A wireless data link 1404transmits cable distance data to the processing unit 112 where they arecombined with data from the inspection assembly 1403 and integrated intothe information display 114.

FIG. 15 is a schematic diagram illustrating a processing flow embodiment1500 for extracting motion vector data from a single image, includingapparent velocity data, surface variation data and track and map data.The size and shape of the inside of the piping system is determined bycomparing the apparent velocity and direction of each camera image pointto the actual camera velocity measured by the cable-counter andaccelerometer sensor. The optical characteristics of the camera lens maybe precalibrated to facilitate correction therefor. The inside walls ofa larger pipe are generally further from the inspection camera,appearing to move slower than the closer wall of a smaller pipe.Variations from a circular geometry also affect apparent velocity of theinside pipe wall image points. Using these characteristic variations,offset joints, transitions in inside diameter, flattened sections; otherpipes joining at Tee's, etc., may be automatically identified andmapped.

In FIG. 15 , digitized image data 1502 are analyzed in software todetect pipeline features 1506. The relative positions 1508 of eachdetected feature over several image frames are analyzed to extract thecorresponding apparent velocity vectors 1510. Independently, cameravelocity data 1512 are acquired from other local condition sensors andcombined with the apparent velocity vectors 1510 to produce a comparisonof multiple apparent pipe feature velocities 1516. These featurevelocities data 1516 may be used to extract the pipe interior size andshape estimates 1514. The comparisons 1518 of several sequential sizeand shape estimates are analyzed to produce a pipeline transitiondetection 1520. Responsive to these results, other calculations may beperformed to resolve the pipe interior conditions at the camera headassembly, the direction and distance of camera travel, etc.

FIG. 16A is an isometric expanded view of a flexible inspection assemblyembodiment 1603 revealing an in-line ferromagnetic Sonde embodiment 1622having a hollow axial tube (not shown) for the passage of electricalconductors and/or fiber optic cables. The Sonde is actuated by means ofa copper winding layer in the cable construction, insulated from thecore. In inspection assembly 1603, the camera head assembly 100 alsoencompasses the accelerometer (not shown) and other local conditionsensors (not shown) and is coupled to a cable construction, a portion ofwhich constitutes a ferromagnetic Sonde 1622, and in which a hollowaxial tube provides passage for electrical conductors 1604 andfiber-optic cable, for example. The composite camera cable containingelectrical conductors 1604 and fiber optic core is coupled by matingplugs to the push cable 101, which then connects to processor 112, whichis connected electronically to the display unit 114.

FIG. 16B illustrates the assembled inspection assembly 1603, includingthe camera head assembly 100 and integrated Sonde 1622 with electricalconnectors 1606, which mate to corresponding connectors 1608 in the pushcable 101. A mechanical push-cable termination assembly 1708 is furtherdescribed below in connection with FIG. 17 .

FIG. 16C is a cross-section of the integrated Sonde 1622, revealing aflexible semirigid hollow axial tube 1623 that is wrapped with one ormore layers of iron wire 1624, which constitutes the ferromagnetic coreof the Sonde 1622. The iron wire layer 1624 is covered with aninsulating layer 1626 on which is wound a layer of copper wire 1628constituting the Sonde's coil. The copper winding 1628 is covered with aprotective cover layer 1630. The two terminals (not shown) of the copperwinding are led through a pin-hole (not shown) into the void 1631 in theaxial tube 1623, where they are connected to a power conductor (notshown).

FIG. 16D is a cross-section of an alternate in-line ferromagnetic Sondeembodiment 1613 without the central tube 1631 (FIG. 16C). With nocentral void, the through wires are passed between the coils and thecore. For example, six copper 28-A WG wires, exemplified by the copperwire 1632, are disposed in the recesses formed by the junction of thecircumferences of seven high-permeability core strands, exemplified bythe core strand 1634, which may be embodied as insulated high-carbonsteel strands, for example. A mechanical filler 1636 wraps about thecore construction and a magnet wire coil 1638 wraps around the wholeperpendicular to the axis of the cable. A rubber or plastic tube 1640slips over the whole 1613.

FIG. 17 shows an alternate embodiment 1700 revealing inner camera cableconductors 1706 and the electrical connectors 1702, 1704 to the camerahead assembly 100. In assembly, the push-cable outer jacket is removedto expose the inner cable conductors over a distance approximately equalto the distance between the camera head assembly 100 and the mechanicalpush-cable termination assembly 1708 of the push-cable 101. Theresilient composite push-cable core is then trimmed back andmechanically fixed to the push-cable termination assembly 1708. Thepush-cable conductors 1706 extend forward to an electrical connector1704, which connects to the back connector 1702 of the camera headassembly 100. FIG. 17 illustrates the camera cable with the outer jacketof the cable removed to expose the inner cable conductors 1706, whichterminate in an electrical conductor 1704. The camera head assembly 100is similarly terminated in a mating electrical connector 1702. Thisconfiguration avoids the need for an electrical termination inside therear spring termination 1708. Alternatively, the pipe mapping system mayinclude an electrical slip ring or an inspection camera push-cablestorage drum having two mechanically and electrically separable parts.The direction of separation may be along the axis of rotation of theslip ring, as is taught in U.S. patent application Ser. No. 10/858,628filed on Jun. 1, 2004 by Mark S. Olsson et al. and entitled“Self-Leveling Camera Head,” which is entirely incorporated herein bythis reference.

FIG. 18A is an expanded isometric view of a slip-ring embodimentsuitable for transmitting electrical power and data signals across arotating storage drum assembly 124 (FIG. 1 ). The direction ofseparation is along the axis of rotation of the slip ring. A magnet isfixed to one slip-ring part to rotate with respect to the other part toprovide an indexing means for measuring the magnitude and direction ofslip ring rotation about its axis in support of a cable feed counter.One separable part of the slip ring is mounted on the rotating cablestorage drum and the other separable part is mounted onto the rotatingcable storage drum support means. The cable storage drum may be removedfrom its mounting frame if a separable electrical connector is providedtherefor. In FIG. 18A, the plug assembly 1802 is shown on the left andincludes a post 1814, a series of contact rings 1804, 1806, 1808 andinsulators 1810, 1812 separating the contact rings from one another. Thereceptacle assembly 1852 includes a mount 1866 and an array of contactpins 1854, 1856, 1858, 1860, 1862, 1864 that are connected to a printedcircuit board 1868. When the storage drum is mounted to the frame (124in FIG. 1 ), the pins 1854, 1856, 1858, 1860, 1862, 1864 come intocontact with the rings 1804, 1806, 1808, thereby connecting the twoassemblies electrically to transfer signals from the conductors withinthe pushrod to devices on the other side of the cable drum, such as theprocessing unit 112 (FIG. 1 ).

FIG. 18B is an expanded isometric view of an alternate slip-ringembodiment having a “pancake” configuration. The contacts are formed bymeans of conductive tracks on a flat circular slip-ring “pancake”surface 1880, which electrically connect to corresponding spring-loadedcontacts on the opposite slip-ring contacts surface 1870. A series ofspring-loaded contacts, exemplified by the contact 1872, are disposed onthe flat circular surface 1880 for seating into aligned slots (formedbetween pairs of conducting rings exemplified by the ring 1876) on themating contacts surface 1870. A hex-headed male cartridge 1874 isdisposed at the center of contacts surface 1870 for mating with acorresponding hex receptacle 1878 on the slip-ring surface 1880, therebyforcing both slip-ring elements 1870, 1880 into alignment uponengagement. The slip-ring surface 1870 also contains an embedded magnet(not shown) that is detected by a fixed Hall sensor (not shown) forindexing rotational movement of the affixed drum with a resolution ofone degree or less to provide cable feed length data.

Two or more wheels may be mounted onto a push-cable storage drumsupporting frame. Also, a telescoping sliding handle may be providedthat extends from two support tubes in the push-cable storage drumsupporting frame. FIG. 1 9A is a rear view of a push-cable storage drumembodiment 1924 showing the frame supported with spring mounts on twowheels 1904, 1906, which are mounted using a spring tensioned suspensionmeans. Axle 1912 is partially flexed and constrained by axle flexor 1914to offset camber in the wheels when under load. This arrangement issimpler and lighter than employing pneumatic tires, for example. Turningto FIG. 19B, a detailed view of the wheels, axle and bottom frameassembly 1930 is shown. In FIG. 19B wheels 1904, 1906, are mounted on anaxle 1912 which is partially flexed and constrained by an axle flexor1914. The dynamic of the flexed axle serves to counteract camber whenthe wheels are under load. Also, the frame is connected to the axle bysprings 1910 inserted into a fabricated slot 1916 and provided with aspring cover 1920, serving to absorb shock while the whole unit is inmotion using the wheels.

FIG. 20 is a front perspective view of the storage drum assembly 1924illustrating the handle 2014 inserted into two support tubes 2010, 2012that form the support for the back side of the storage drum assembly,thereby forming a telescopically extendable handle. An exemplaryconfiguration of the cable drum 1902 and its rotary hub 2008, a singlecentral back support tube 2016, and adjacent molded plastic frame, arealso illustrated. The assembly 1924 is provided with two wheels (onlywheel 1906 is visible) to facilitate convenient relocation of thestorage drum assembly 1924. The drum axis of rotation is perpendicularto the long axis of support tubes 2010 and 2012.

Another configuration of the cable storage drum and support assembly isdepicted in FIG. 21 . In one embodiment, where one or more supportmembers form the sole support means for one side of a rotatinginspection camera cable storage drum supporting means, and further whereone or more removable rechargeable batteries may be mounted to thesupport structure joining said one or more support members to therotating inspection camera cable storage drum.

FIG. 21 is a front perspective view of another storage drum embodiment2124 revealing the additional battery holders 2102, 2103 mounted, forexample, to the molded plastic frame member 2106. Battery holders 2102,2103 may be mounted at any other useful location in the frame structure.An exemplary rechargeable embodiment of batteries 2104, 2105 is shown.FIG. 21 also shows exemplary embodiments of the handle 2014, handlesupport tubes 2010 and 2012, frame support tubes 2002 and 2004 and lowermolded frame 2108. FIG. 22A is a detail view of an exemplary storagedrum assembly handle embodiment illustrating the joint between a moldedplastic frame member (e.g., 2110 in FIG. 21 ) and a support tube (e.g.,2004 in FIG. 21 ). In this embodiment, a joint is formed by inserting asupport tube 2004 into a receiving hollow or hole in a molded plasticframe member 2110.

FIG. 22B is a detail view of the joint of FIG. 22A illustrating thedisposition of two pressure-expanded dimple elements 2206 and 2208,which are formed in the metal of the tube 2004 using a hydraulicallypressurized swaging tool or other means and which fix the tube 2004 intothe molded plastic 2110 by expanding a protrusion on either side of thetube as shown. FIGS. 22C and 22D show two variations on the swagingtechnique. In FIG. 22C, the expanded elements 2206 and 2208 of tube 2004fit to a groove 2210 formed in the molded plastic component 2110. InFIG. 22D, pre-formed holes 2214 and 2216 are disposed to receive theexpanded elements 2206 and 2208.

FIG. 23A is a cutaway side view of a partially disassembled inspectionassembly embodiment revealing the camera head assembly 100, thepush-cable 101, the terminating assembly 1708 (not shown), the lockingdevice 2304, the coil spring 2306, and the internal connectors 1702 (notshown) and 1704. FIG. 23A addresses the construction of a typicalinspection assembly and cable with a protective helical spring. Thesmallest inside diameter of the spring 2306 is larger than the largestoutside diameter of the push-cable termination assembly 1708 (withspring locking device removed), allowing the elongate spring 2306 toslide away from the camera head assembly 100 over the push-cabletermination assembly 1708 and onto the push-cable 101, thereby exposingthe internal connectors 1702 and 1704. After repair or servicing, theelongate spring 2306 slides back over the inspection assembly 1703 andthen is secured in place with a spring locking device 2304 that mountsonto the push-cable termination assembly 1708. A termination assembly1708 at the connecting end of the push-cable holds a spring lockingdevice 2304, which holds the spring in position when put into placeduring assembly. The tip of the spring wire at the camera-head end ofthe elongate spring 2306 is received into a matching groove in thecamera head assembly 100, thereby locking it at the forward end ofinspection assembly 1703. FIG. 23B illustrates the same elongate spring2306, camera head assembly 100, and push cable 101 in an assembledconfiguration. In FIG. 23B, elongate spring 2306 is retained by lockingdevice 2304.

FIG. 23C is a cutaway side view of an alternative fully-assembled camerahead assembly embodiment 2303. The push-cable 101 joins to a connector2302 that also seats the elongate coil spring 2306. Within the coilspring, the in-line Sonde 2314 is electrically connected to connector2302 at one end and to an attachment means 2308 at the other end.Attachment means 2308 is connected to a coil cord 2310 capable of enoughextension to prevent strain from putting the electrical connections atrisk of detachment during flexion of the unit. The coil cord 2310 endsin a connector 2312 that joins to the power, data and video pins of thecamera head assembly 100.

FIG. 24A is a front perspective view of the storage drum of FIG. 19 withan exemplary display monitor embodiment fixed to the storage drum frameand fitted with a hinged integral U shaped sun hood. In FIG. 24A theU-shaped sun screen 2402 is shown mounted to the frame member 2406, witha system display unit 2408 mounted onto it in such a manner that theextended hood provides shade to the display screen 2404 improvingvisibility. FIG. 24B illustrates the hinging action of the sun shade2402. Horizontal hinge 2412 and vertical hinge 2410 allow positioning ofsun hood 2402. FIG. 24C shows an alternate configuration of the sun hood2402 attached to the cable storage drum support system 124 and foldeddown for transport in such a way that it protects to the display screen2404.

FIG. 25A is a schematic diagram of a cable drum embodiment having animage cable for transferring image data and a wireless transmission unitfor transferring local condition sensor data to the processing unit; inone embodiment, all or some inspection camera data, except camera imagedata are transmitted by wireless means from inside the rotatinginspection camera cable drum to a separate data processing unit orcombined data processing unit and image display means. In FIG. 25A thepush-cable 101 containing electrical conductors carries data from theinspection assembly 2503 to the cable storage drum 124. Except for theimage data carrier, all the data channels coming from the inspectionassembly 2503 terminate at a wireless transmitter 2506 situated, in thisexample, inside the cable drum assembly 1902. A wireless data link 2502transmits local condition sensor data and Sonde data to the system dataprocessor 112 while the image data are transmitted to a connector at thedata processor 112. The data processing unit 112 integrates imageinformation, local condition sensor data and time tags and assembles theinformation for display at the display unit 114. Video information mayalso be transmitted wirelessly as will be shown in FIG. 25B.

FIG. 25B is an alternate embodiment of the storage drum of FIG. 25Ahaving a wireless transmission unit for transferring all data to theprocessor; In this embodiment, all or some inspection camera data,including camera image data are transmitted by wireless means frominside the rotating inspection camera cable drum to a separate dataprocessing unit or combined data processing unit and image displaymeans. In FIG. 25B the wireless transmission unit 2506 transmits alldata being carried on the cable 101 from the inspection assembly 2503including images from the camera head assembly 100. Images may beconverted at the cable drum into digital representation from thefiber-optic cable shown in FIG. 7A (710), or they may be converted bycircuitry within the camera head assembly 100 or inspection assembly2503 and transmitted as digital data on an electrical conductor. Thecable storage drum support frame may also incorporate a tool receptaclefor the storage of wrenches, gloves and other tools commonly needed inlocating operations. The cable storage drum may also support a USBinterface, for example, for the direct transfer of data to a portablecomputing device.

FIG. 26 is a front perspective view of a storage drum embodiment 2624having a tool tray or box 2602 mounted to the back of the vertical framesupport tubes 2604 near the handle 2014 and having a USB data port 2610fixed to the cable-drum support frame 2616 for linking to a laptop 2614for exchanging data. The processing and display units of the cable andcamera system may be connected wirelessly or by wire to a DVD unitcapable of generating DVD recordings of pipe inspection imagesimmediately following an inspection. FIG. 26 shows a tool storagereceptacle 2602 mounted directly on the vertical frame support tubes2604 but storage receptacle 2602 may also be fixed to the upper moldedplastic support frame 2606, for example.

A USB data port 2610 is shown integrated into the lower frame assemblyon the back. In this example, the USB port 2610 is connected by a USBcable 2612 to a laptop computer 2614 acting as a display unit. The USBport 2610 may be located elsewhere in the frame assembly at anyconvenient location such as upper molded plastic support frame 2606, forexample.

The system of this the disclosure is directed to processing and displayunits having an interface to a removable media device (such as USB thumbdrive or a SD or CF memory card slot) that facilitates recording ofcamera data, audio, still images and/or videos to the removable media.FIG. 27 is a schematic diagram illustrating a processing embodiment 2700for transferring inspection assembly sensor data packets to theprocessor for rendering an exemplary display image showing the insertionof local condition sensor data displays in the margins around a circularimage display. The pipe mapping system embodiment may include a voiceinterface by which user commentary is recorded with time tags correlatedto the corresponding image and data store.

In FIG. 27 , incoming inspection assembly sensor data includeaccelerometer data 2702, compass data 2704, temperature sensor data2706, and an analog voice capture signal 2708, which is transformed todigital voice data by an ADC 2710. These digital voice capture data 2710are associated with contemporaneous digital time tags 2712 andtransferred to a data processing unit 2714. All data packet streams areaccepted and coordinated at the data processing unit 2714 for storage ina volatile memory (not shown) from where they may be transferred underprogram control to a permanent data store 2716 for possible storage andto the display 2718 for possible display to an operator and presentationto the DVDR unit 2720 for recording under operator control, for example.In the display 2718, key data may be rendered as images for insertion inthe margins around the central circular image display 114, for example.These graphical formats may be user-configurable through softwareconfiguration.

The pipe mapping system of this the disclosure may include a voiceinterface by which user commentary is recorded with time tags correlatedto the corresponding image and data store. A durable wireless controllermay be provided to facilitate remote operator control of elements in thepush-cable storage drum and inspection assemblies, such as camera headassembly, cable drum motor, voice signal recording and othermanually-controllable system elements, or example. FIG. 28 is aschematic diagram of a pipe mapping system embodiment 2800 illustratingthe use by an operator 2802 of a wireless remote control transmitter2804 to transmit a wireless signal 2805 incorporating, for example, avoice signal for recording or various control commands to the camerahead assembly or other manually-controllable system elements by way ofthe processor 2808 (not shown). In one embodiment, the pipe mappingsystem includes a durable remote control transmitter facilitatingoperator control of various system functions. In FIG. 28 a scenario isdepicted illustrating this embodiment, in which an operator 2802 isequipped with a remote control device 2804 while operating the pipeinspection system. The display 2806 is mounted on the frame of the cablestorage drum assembly 124 and is integrally attached to a processor unit2808. The remote control transmitter 2804 may be operated to controlvoice and image recording, cable drive motor operation, and displayconfiguration options, for example.

Another pipe mapping system embodiment includes one or more diode lasersand an associated diffraction grating or holographic element assemblyfor use as a source of structured light illumination for the videocamera, thereby facilitating acquisition of dimensional informationsuitable for establishing the 3D character of the interior of the pipeunder inspection. FIGS. 29A-C are schematic diagrams illustrating astructured-light techniques adapted for use in a laser-driven pipeinspection camera lighting unit of this disclosure. At least one diodelaser emitter is provided as the camera-head light source, coupled witha pattern projection means such as a diffractive film or grating or aholographic element to create a structured light pattern within the pipewhose reflections may be used to develop 3D mapping of the pipe interiorusing any useful technique known in the art.

In FIG. 29A the structured lighting assembly 2900 is shown fixed to thecamera head assembly 2902 and includes two diode laser light sources,exemplified by the diode laser source 2904, but any useful number ofthese sources may be included. Laser light from source 2904 is directedthrough a diffraction grating 2906 causing the projection of astructured light pattern 2910 within the pipe. An imaging detector 2908senses the reflection of laser light from the interior pipe surfaces onwhich the pattern falls. These image data are combined in the processor(112 in FIG. 1 ) with other information such as, for example, camerahead assembly orientation, location and rate of movement relative to thepipe interior. This additional information facilitates operation of thestructured light system 2900 as a dynamic optical ranger. Emission ofthe predefined image pattern provides a basis for recovering thedistortion of the reflected pattern for use in characterizing thesurface irregularities within the pipe under inspection by producing apoint by point analysis of the two digitized images (sent and returned).

FIG. 29B illustrates several transmitted image patterns useful for thestructured light method of this disclosure. Clearly, any practitionerskilled in the art can appreciate that a more complex patternfacilitates more detailed reconstruction of the pipe interior.

FIG. 29C illustrates a camera head assembly 2902 equipped with astructural lighting assembly disposed inside a pipe 116 underinspection. Two laser emitters 2904 are disposed behind a diffractiongrating 2906 to produce a structured light pattern directed along thebroken lines to illuminate a region of the pipe interior within the FOVof image detector 2908, including a surface irregularity 2914. Thedetector 2908 captures FOV images of the light reflected from the innerpipe surface and the processor (not shown) compares these FOV image datawith the predetermined structured light pattern to produce Cartesianrange data at a predetermined image frame rate. These reflective changesin pattern received at the camera detector 2908 provide the basis forcalculating pipe wall surface characteristics in the system dataprocessing module, which then facilitate the rendering of a 3D image ofthe interior pipe surfaces when location and orientation data from otherinspection assembly local condition sensors are processed to resolvecamera head assembly movement and orientation. This system may usefullyemploy a visualization subsystem for acquiring a voxel array filled withred, green and blue (R, G, B) image detector output values at X, Y and Zlocations using a registration technique such as the Fast Landmark Graph(De Piro, CalPoly) method to isolate subgraph isomorphisms, or similarmethod, for example.

Clearly, other embodiments and modifications of this disclosure mayoccur readily to those of ordinary skill in the art in view of theseteachings. Therefore, the presently claimed invention is to be limitedonly by the following claims and their equivalents, which include allsuch embodiments and modifications when viewed in conjunction with theabove specification and accompanying drawings.

The invention claimed is:
 1. A method for mapping pipes underinspection, comprising: generating, from a video inspection camerainserted into a pipe, a plurality of images of the interior of the pipe;determining, based at least in part on the plurality of images, anestimate of a diameter of the pipe in the area of the pipe where theplurality of images are generated, wherein determining the estimate ofthe diameter of the pipe includes: measuring an apparent velocity and adirection of at least two camera image points: and comparing theapparent velocity and direction of each camera image point to an actualcamera velocity measured by a cable-counter and an accelerometer sensor:and storing the determined estimate of the diameter of the pipe in anon-transitory memory.
 2. The method of claim 1, wherein the videoinspection camera includes an image sensor disposed at the front of acamera head assembly.
 3. The method of claim 2, wherein the image sensorincludes a field of view (FOV) including an entire circumference of apipe under inspection.
 4. The method of claim 1, further comprising atemperature sensor.
 5. The method of claim 1, further comprising agyroscopic sensor.
 6. The method of claim 5, wherein at least one of theaccelerometer and gyroscopic sensor is used to compute angular rotationof a camera feed comprising the plurality of images.
 7. The method ofclaim 6, further comprising producing a correctly oriented circularradar scope display image using output data from at least one of theaccelerometer and gyroscopic sensor.
 8. The method of claim 7, furthercomprising a display for rendering the radar scope display image.
 9. Apipe inspection apparatus, comprising: a push-cable; a video inspectioncamera mechanically coupled to the push-cable; a cable counter: anaccelerometer; and electronics, including a processor and anon-transitory memory, to receive a plurality of images generated in thevideo inspection camera, determine, based at least in part on theplurality of images, an estimate of the diameter of the pipe in the areaof the pipe where the plurality of images are generated, whereindetermining the estimate of diameter of the pipe includes: measuring anapparent velocity and a direction of at least two camera image points:and the apparent velocity and direction of each camera image point to anactual camera velocity measured by the cable-counter and theaccelerometer; and store the determined estimate of the diameter of thepipe in the non-transitory memory.
 10. The apparatus of claim 9, whereinthe video inspection camera includes an image sensor disposed at thefront of a camera head assembly.
 11. The apparatus of claim 10, whereinthe image sensor includes a field of view (FOV) including an entirecircumference of a pipe under inspection.
 12. The apparatus of claim 9,further comprising a temperature sensor.
 13. The apparatus of claim 9,further comprising a gyroscopic sensor.
 14. The apparatus of claim 13,wherein at least one of the accelerometer and gyroscopic sensor is usedto compute angular rotation of a camera feed comprising the plurality ofimages.
 15. The apparatus of claim 14, further comprising producing acorrectly oriented circular radar scope display image using output datafrom at least one of the accelerometer and gyroscopic sensor.
 16. Theapparatus of claim 15, further comprising a display for rendering theradar scope display image.